IN NEED OF LOCAL ACRYLIC WIZ

#1 all acrylic is not created equal

#2 WO 16 is good for a few things, and creating corner seams for water-tight vessels is not one of them.

You need a good extruded material like Plex-MC or Acrylite FF at a minimum. Cell cast acrylic is best but kind of overkill for a sump.

Weld-on #3 minimum, #4 preferred, make-your-own is ideal.

You need to get all this from an acrylic supplier, not your local hardware store - that stuff is no good for tanks.

There is at least one place in CR but can't remember the name. Another one opening on 9/1. Some places will cut pieces to order for a few $$. But those will be rough-cut with a table saw and will need edge prep before bonding, either by scraping with a razor blade or on a router table.

However you do it, you need to let it sit for a week before putting water in it. You can't rush this unfortunately. If you do, the newly solvent welded joints will absorb water faster than the rest of the material and cause different expansion rates, and you could have problems down the line.

So if you need it rushed, you might want to consider taking a glass tank and siliconing in some dividers, then taking the time to have the acrylic sump made exactly how you want it, and done right.